… That you can make yourself
A good tuning grease for non-moving slides such as tuning slides and 2nd. valve slides is anhydrous lanolin, you’ll be able to find it at a Pharmacy located in the ‘Baby’ department. You can also order this in a large jar as well.
A good slide grease for moving slides is (you’ll have to make this yourself), Take anhydrous lanolin, place it in microwaveable container, with 50% petroleum jelly, mixed with 50% anhydrous lanolin, now warm or melt these two together.
After they liquefy, and begin to cool, pour into a non breakable container, set it aside and let cool into a paste. Depending on the time of year and temperature, you can adjust the consistency by adding more anhydrous lanolin, if you want it to be stiffer, or add more petroleum jelly if you want it to be not so stiff.
It’s also dis-solvable by valve oil so it shouldn’t gum up the horn. However if you use too much and it does, as too much slide grease could make the whole trumpet sluggish so if this should happen just give the horn a soap and water bath, and swab out the valve casings using a soft cloth with a valve cleaning rod.
Put a small amount in a container with a snap-on lid and keep it in your case. Just make sure it is tightly closed and won’t leak out in hot weather.