i used a couple of those multi-purpose/position head bands under my helmet and around my face. they're only 170php at decathlon and cheap in department stores as well.

multi-purpose-head-face-mask-snood-bandana-neck-_1.jpg

the helmet that was handed to me for use wasn't stinky naman. they probably do clean and wash those inner linings regularly as part of angkas' rules. but still i suggest wear some sort of cap between your head and the helmet pa din. or as mentioned here before, if you plan to use angkas regularly, get your own helmet instead so you can wear a properly fitted one.