And your proof ?The safest glasses to drink in a hotel room are those cheap plastic cups wrapped on the kitchen sink usually found in budget hotels. I've seen cleaning staff clean with the same dirty rag they wipe other surfaces with the drinking glasses by the ice bucket. Speaking of the same dirty rag, before your ordered entree leaves the kitchen, the kitchen staff wipes down your clean plate with the beautifully plated food presentation with a dirty cleaning rag ( fact ). I've been in the business.