Well I gave it a try this morning. I didn't have a 100% brand new propane tank, but one that was pretty much full. I put 5ml of wintergreen oil in it and gave it a good shake. Filled up an impact 'nade to blank fire and while filling, my madbull adapter was leaking at the fill valve a bit and you could smell the wintergreen along with the propane. After blank fire you could smell the wintergreen in the air with the propane. It does help mask the mercaptan odor some. Not sure if it will mask the acetylene that makes mapp gas stink real bad.
Need to invent some sort of carbon scrubber filter to strip the stink out.
Even now, like 5 min after testing, the wintergreen/propane scent still lightly lingers in the air.