I use my Class 0's all the time for tying in service drops, working in hot meter enclosures, handholes or pretty much any time I feel there is a high probability of shock.
One thing I would definitely recommend getting is a bottle of glove dust.
This is the only thing that makes these clammy gloves tolerable for extended wear, at least as far as I'm concerned anyway.
I check my Class 0 gloves and leathers before each use and will also test the rubbers annually by throwing them in the trash and replacing them every year since they’re not too expensive without the leather protectors.
Once they get inhibitor or any petroleum based product on them, which is hard not to do, it seems like the clock is already ticking anyway. Sunlight and oxygen eat them up as well, even when stored in their case, I've noticed. Over time, they can end up with soft spots in the palms or oxidation and check marks all around the rolled rubber cuffs.
I'd say if they are Class 0 or 00, unless you already have your own glove tester, I think it is more cost effective to just replace them at regular intervals.
If they are Class I, II, or III gloves, then they are a much more expensive investment and unless noticeably damaged are most likely well worth the cost of testing.
