I picked up some Berp BioLube a while back in anticipation of receiving my Butler JJ build, as I understand it works well for the Butler slides. In the meantime, I've been using it on my regular slides, and I like it well enough that I looked into what other products they offer. I see that they have a BioOil listed for rotor valves:

[url]<LINK_TEXT text="https://berp.com/collections/biooil/pro ... iorotoroil">https://berp.com/collections/biooil/products/biorotoroil</LINK_TEXT>

It comes in a few different viscosities. I was curious as to whether anyone has tried this product and if so, which viscosity did you go with? I posed the question on their site, looking for recommendations, but they seem a bit slow to respond.

I bought a bunch of it. The medium is pretty thick, so most rotors would benefit from the light. In the end, I thought Hetman's still worked better - lasted longer and felt quicker, so I went back to that. I do like the slide lube a lot, though! Everyone's body chemistry works differently with different oils so my advice may not work the best for you.

Thanks! I did get a response from Berp, and Miles also recommended the light viscosity for trombone rotors, so I'm going to give that whirl and see how I like it.

When I got my Butler C10 (used) it came with some Berp light rotor oil and I’ve been using because I’m afraid other oils might not mix well with the slide lube. It seems to work fine and I don’t see the yellowish gunk that I’ve found with Hetman’s. I think a slightly thicker oil might be good for the linkage so I’ll get some when I order more for the rotor.