Completely non-Blam related, Biodegrader is a Deathmatch fixer plugin currently under development and testing by Badlands, as well as a brave few others. Due to the lack of a major HL distribution center, I've posted a copy of it here, so anyone willing to try it out and file bug reports is welcome to grab it and give it a whirl.
It works just like Clumpfix, in that the host just needs to activate it, and the players just need to have it. When active, it will gradually cause projectiles to expire, preventing the map from overflowing (the principle bug with Deathmatch). It's subtle, but it works great... so far.