Can oil based products (e.g. shea butter, coconut oil) and products that contain MSM the night before affect laser hair removal?

Laser tech said she couldn't treat my skin bc I used shea butter as a moisturizer the day before and oils can fry the skin. She recommended me wait 3 days to reschedule. My second time going in I tell her I switch to a water-based lotion with MSM in it, and she said that MSM was an antibiotic (it's not) and that she couldn't treat my skin. She now pretty much wants me to not use any moisturizers, except sunblock post treatment. Does this sound right? I'm getting whole body laser hair removal.