I got this $17 and another one about kinda same price (but smaller) from Muji Japan. https://www.amazon.com/Samsonite-Microbead-Neck-Pillow-Frost/dp/B075B48B3B/ref=sr_1_3?crid=26VCPM8QSMBAS&keywords=samsonite+microbead+3-in-1+neck+travel+pillow&qid=1688154360&sprefix=samsonite+microbead+%2Caps%2C211&sr=8-3

You just remove the inside and put your socks/ undergarment in there... just fine. Never seen an airline weighting a neck pillow. It's been working for me so far.