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I've used Space Filler green label (the thick stuff). I can't say it holds up all that well to moisture, but I've had no trouble with it gumming up the valves either. And did you notice the side ad for vaginal dryness on this topic? Hmmmm.

I used axle grease until my tuba tech told me to switch to white grease in a spray can.

I've had excellent results using Hetman #4 Light Tuning Slide Oil on my snug-fitting slides.

It has also "lasted" well on slides that regularly get pulled for dumping.