Pulse, when installed, will unconditionally overwrite your carefully crafted .asoundrc settings that, for instance, use an environment variable to choose the ALSA device on which to output.  This is one of those things that everything tells you "is good", without telling you how it happens, or how to stop it.  Long story short, the offending file is: /usr/share/alsa/pulse-alsa.conf .  Take off and nuke it from orbit, it's the only way to be sure.