I have only once bought clothes on ebay, and that was at least 5 years ago. The garment, a winter coat, was too all appearances brand new, so I didn't see any need to get it dry cleaned.
Charity shops are meticulous about making sure clothes they put out are clean, and I wouldn't dream of giving to a charity shop any clothes that were not freshly washed or drycleaned and I haven't ever bought any whose cleanliness I suspected.
Funny how people always assume that other people are the ones with filthy habits that threaten our health. That is how they see us.