Fluorescent bulbs - how to install a difficult one without breaking it?

I have two 20-inch fluorescent fixtures which I got from my local hardware store. I guess they’re “standard” and typical for home use (IANAelectrician and wouldn’t know the difference if they weren’t).

I installed these fixtures in my lizard cages. As such I use special UV bulbs which need to be replaced about every six months or so. (After six months the bulb will still light, but is no longer emitting enough UV radiation.)

So… I’m frequently changing fluorescent bulbs (‘tubes’?). Other than the UV output they are standard bulbs, i.e. they have two pins on each end, and are installed by inserting both ends into the receptacles and rotating the bulb about a quarter turn until it ‘clicks’ in place.

Over the years it has become more and more difficult to get the bulbs in and out. Specifically: the ‘rotating’ part of the procedure. I have to use what I consider to be an excess amount of force, and it’s my understanding fluorescent bulbs are rather fragile. I’m afraid I’m going to break one, cutting myself and spreading glass shards around the cage.

What can I do to make these things go in easier?

I thought of WD-40, but it’s quite flammable and I’m not sure it would be a good idea to use it directly on an electrical appliance. What if I used WD-40 but let it dry an hour or two before I turned the lights on?

How about powdered graphite?

Well, I know exactly what you mean, because I have 20 watt fixtures on my fish tanks. Found this, FWIW, under a Google search for “graphite fluorescent fixtures”:

http://www.kinoflo.com/sales/faq/faq.html#lubricate

      • IIRC, graphite powder is conductive and is a Really Bad Idea to use around electric -n- electronic stuff that you care about. - MC