If you're near a Walgreens, I've had luck finding this or similar, and it works well - https://www.walgreens.com/store/c/no-rinse-moisturizing-body-wash/ID=prod3946589-product
Depending on where you're at, or if you're able to ship Amazon to a locker, etc., these are awesome for a simple fresh clean - https://www.walgreens.com/store/c/no-rinse-moisturizing-body-wash/ID=prod3946589-product
And if you check Walmart, you may or may not have luck finding something along these lines - https://www.walmart.com/ip/Grime-Boss-Field-Wipes-24ct/55302028 - It really depends which Walmart you're at and your part of the country. Some have bath/shower wipes with all of the other personal hygiene/bath products. Some only have them back in the camping/outdoor sections. Some have multiple varieties in both places, and some don't even sell them at all.
I also have a solar shower like - https://www.amazon.com/Coleman-2000014865-5-Gallon-Solar-Shower/dp/B0009PUT20 - which you can definitely find a lot of places, though I don't really use it.
I keep all 4 of these things in my van along with my other "normal" shower, all in a 5 gallon bucket - https://www.amazon.com/Ivation-Portable-Outdoor-Battery-Powered/dp/B00IFHFJXI, which can be used in any water source. You may have luck finding it at Walmart, but a better chance at an outdoor store like Bass Pro Shops, Cabellas, Gander Mountain, or REI
Battery powered shower head and a 2 dollar bucket from walmart for showers. We used it everyday last year and our neighbors even asked us if they could pay us to use it. We also bought a little shower tent for some privacy.
Ivation Portable Outdoor Shower, Battery Powered - Compact Handheld Rechargeable Camping Showerhead - Pumps Water from Bucket Into Steady, Gentle Shower Stream https://www.amazon.com/dp/B00IFHFJXI/ref=cm_sw_r_cp_api_i_559YW9GEH62AC57C4PXS?_encoding=UTF8&psc=1
https://www.amazon.com/gp/product/B00IFHFJXI/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
I bought these and just use a 5 gallon bucket with water ive heated up on a grill, its game changing being able to shower in camp
Shower Tent: https://www.amazon.com/gp/product/B01AT3SZ36/ref=ox_sc_act_title_10?smid=AA9QUDWBLIJKI&psc=1
Shower Head: https://www.amazon.com/gp/product/B00IFHFJXI/ref=ox_sc_act_title_22?smid=A2LM6ZPY06LT1N&psc=1
or you can go ahead and use a solar bag shower: https://www.amazon.com/Coleman-2000014865-5-Gallon-Solar-Shower/dp/B0009PUT20/ref=sr_1_10?s=sporting-goods&ie=UTF8&qid=1550432756&sr=1-10&keywords=solar+bag+shower
We had an upright Nemo. Kept it full for several months at a time while traveling. The valve on the foot pump eventually failed and leaked about 5 gallons of water in our van, practically ruining our laminate floors. We now have a portable, rechargeable shower that we put in a large opening water container. The container will never fail, and it serves as extra water if needed. https://www.amazon.com/Ivation-Portable-Outdoor-Battery-Powered/dp/B00IFHFJXI/ref=mp_s_a_1_3?crid=O5BUIF059YZ0&keywords=portable+shower+head&qid=1680368297&sprefix=portable+shower%2Caps%2C198&sr=8-3
https://www.amazon.com/Ivation-Portable-Outdoor-Battery-Powered/dp/B00IFHFJXI
You could just get this and drop it in a bucket of water.
You can. It's basically what a water tank is, an enclosed bucket connected to a pump. You just need to make sure your pump carries more water per minute than your heater can put out, because running the heater with no water in it is bad.
SO if the heater puts out 4 gallons per minute (gpm) the pump needs to be able to provide 4 gpm or more. Preferably more, since you will also be providing cold water to cool down the hot water. Make sense?
Honestly, don't cheap out on hot water.
Neither of the two you posted are designed for indoor usage. So there's that. The second one seems to be the all in one solution you are looking for.
If you REALLY want cheap, heat your water to the temp you want, put it in a bucket, and use this:
https://www.amazon.com/Ivation-Portable-Outdoor-Battery-Powered/dp/B00IFHFJXI/
Yes, they have several water filling stations throughout the campgrounds and festival grounds. I suggest taking some 5 gallon buckets with lids, a collapsible wagon, and a rechargeable shower head
Ivation Portable Outdoor Shower,... https://www.amazon.com/dp/B00IFHFJXI?ref=ppx_pop_mob_ap_share
It’s probably too late to order anything from Amazon before the festival at this point but I still linked the shower head I bought for Okee in 2020 and still use three years later.
Also bring some sort of tube to guide the water from the faucet into the bucket at the filling station. Last year they were set up like sinks so it was impossible to fill the bucket directly from the faucet and I had to use my Camelbak hose to guide the water.
We’ve done this!
Buy a 5 gallon bucket to fill with water. Can use the water station and let the water warm up in the sun before each use. Then use:
Portable changing/shower tent: Portable Pop Up Dressing/Changing... https://www.amazon.com/dp/B07BWCQV6T?ref=ppx_pop_mob_ap_share
Portable Showerhead: Ivation Portable Outdoor Shower, Battery Powered - Compact Handheld Rechargeable Camping Showerhead - Pumps Water from Bucket Into Steady, Gentle Shower Stream https://www.amazon.com/dp/B00IFHFJXI/ref=cm_sw_r_cp_api_i_ZD6DFH7QHF23ME5X734Q?_encoding=UTF8&psc=1