when my snake had eye caps (her eyes were grey), i soaked her but it didnt come off (i didnt use towel trick), so i just had the vet do it. but man i was dumb LOL.
i see that pillowcase idea working perfect. if not, just soak her, and use a wet cotton swab to rub her eye (applying no pressure) thats wut the vet did

and when i left my snake with eye caps it didnt eat. but as soon as they came off, my snake took a meal, and has never turned back