I reccomend the Elation UV wash as well. I've used it for several shows and haven't been disappointed yet. If you're looking for something that pumps out alot of UV light - try contacting your local rental company and see if they carry any Wildfire UV fixtures.
Hmm, I remember this question being asked more than once here, much less on Pro Sound/Lighting, Stagecraft, and Lighting Network. Lots of choices out there in opinion. Perhaps it should be a FAQ type of thing in checking past posts on the question before posting again.
While I have no problems with re-posting to get fresh info on a question, one should summerize what effort in the study you have already done than ask for more or fresh opinoins of what others do. This way you more build up a base of knowledge of past advice and keep it allive by asking others to add to it.
This rather than thinking you are the first ever to ask the question and expect everyone to re-respond every time the question comes up.
Sorry if long in explination of intent but this question has been asked before. In discussion it would be good to note in re-activating the question what others in advice already have posted in more broadening the solutions given by way of many agreeing with a certain set of color choices or of new unique ones not thought of.
Just a thought. I for instance might attempt some soft wash of lavender with a more harsh beam of blue for my own effect. This given no black light is avaiulable and as per Stagecrafts' past discussion on it, Arco starch was used as much as possible on all surfaces to be lit in some way so as to phosphor.
I realize that this doesn't exactly fit your question as it is not a gel, but Woods Glass can be used to create a focusable form of blacklight. I know Rosco manufactures it in various sizes for use in lights, but i'm too lazy to look for a link.
Woods Glass (a.k.a. Cold Mirror) is a form of dichroic glass filter. Dichroic filters work by reflecting some wavelengths of light, yet allowing others to pass through. In this case, UV passes through while most of the visible light is reflected back into the instrument. The glass doesn't heat up from the light, and never burns out. (Gel works by absorbing certain wavelengths and turning them into heat, I believe.)
The downside? Cost. It costs much more for glass than gel.
We're looking at buying a couple of small rounds so that we can try them in a couple of inteligent instruments that we just bought. In this case, the lamp has more UV output that standard instruments and standard lamps, so we figure that it should turn out pretty well.