Just buy some Zeiss wipes, diabetic injection swabs or even eyeglass swabs. Camera store, pharmacy, gun store (I use Zeiss wipes on my rifle scopes).
You only need one per eyepiece.
I use these all the time on my glasses (glass and acrylic) and even used them on telescopes before:
https://www.boots.com/opticians-serv...s-20s-10190796 - note the ingredients: Isopropyl Alcohol, Water, Fragrance.
Amazon UK:
https://www.amazon.co.uk/BD-Alcohol-.../dp/B0010L6H1Y
Zeiss:
https://www.amazon.co.uk/ZEISS-Lens-...sr=1-3-catcorr
https://www.amazon.co.uk/Carl-Zeiss-...sr=1-1-catcorr
IPA in general:
https://www.amazon.co.uk/s?k=isoprop...nb_sb_ss_i_1_9