Originally Posted by tolovemoon

I don't know if this was the best idea, I used WD40 twice, when I didnt have anything else. It didnt hurt my trumpet, though it did leave a bit of slime like residue thicker than the regular valve oil mixed with ya know saliva moisture. I had to wipe the valves down pretty good
The worse thing to use is cooking oil, vegetable oil is way too thick...Though for a quick fix when in need you could get a day of tolerance using it. The valves just get a little more slimy than usual...