I've been playing around with some stuff I found, but it's not "ball plug."
It's just urethane with a hardness of 75. They have 2 types, one that dries off-white or beige, and one that dries almost clear. I bought it mainly to try to pour custom thumbs.
Only downside is that it has a gel time of 2 1/2 minutes, so you really have to be quick! I've had it set up in the middle of a pour.....basically ended up with a ball with a nice stream and a cup on top. It was pretty cool looking and I probably should've taken a picture....maybe next time.
It has a demold time of 15 minutes, but complete cure time is listed as 24 hours. I poured some holes, went to dinner. Came back about 2 hours later and drilled the holes without any problems. The drilled holes felt really nice, so I don't think it will any problems for using it for custom slugs, once I get the rest of the stuff.
I don't have my router hooked up yet, so I haven't tried to pour a full plug and work the material down, so I can't comment on that part of it yet.
At around $20 for 2 quarts and $60-75 for 2 gallons, it's around half the cost of Wizard and other plug material.
For colors and dyes, I found some plastic/resin dyes and pigments from a craft website. They were $4-5 an ounce. Really haven't had a lot of time to play around with the plugging stuff, but so far I've been happy with the results.
--------------------
FAQ:
http://www.ballreviews.com/Forum/Replies.asp?TopicID=74110&ForumID=16&CategoryID=5Search Ballreviews entire database here:
http://www.bowling-info.com/Search.html