Can you touch the tubes?

For some amps it's difficult to use the base of a tube to push and pull into socket. I found if I just grip it comfortably around the upper portion of the tube and rock it back-and-forth while applying pressure as it slides in.  Of course there's always a fear the glass will shatter but I spread the distribution of my fingers which I think reduces the risk.

If you try to squeeze an egg in your hand with a lot of pressure it won't break but if you start angling your fingers into the egg it will break. I'm not gonna try this with a tube.

if The tube shatters who knows what happens at that point aside from losing 50 to 100 bucks on the tube and debris field. 

I have the Audio Research Ref 750s and they have about 36 KT150s. I use my bare hands. Never had a problem. Oh and about white gloves ? Never ever white gloves. Only use black gloves. 😂

Yes you can touch them 

For better grip I use nitrile gloves. 

I believe this train of thought comes from warnings on head light bulbs in the auto industry.

Quote: When changing the headlight, highbeam or foglight bulb on your vehicle, it is of paramount importance that you not touch the glass part of the bulb with your bare fingers. Oils on you hands will cause the section of the bulb that you touched to get much hotter than other areas of the bulb and will lead to the bulb burning out much quicker. If you do happen to touch the glass part of the bulb, take a solvent like rubbing alcohol and clean the globe thoroughly before installing it in your vehicle. This will remove the oil and the unwanted hotspots.