Just stumbled across this post. For those people not too tech savvy MasterPool.EU provides a very easy step by step procedure to get a firefox .bit enabled:
https://www.masterpool.eu/proxy.
For those of you who are already using Foxy Proxy and don't want to overwrite your existing configuration just add
http://proxy.masterpool.eu:8080/ for .bit Domains. But please keep in mind, that MasterPool Proxy is
ONLY proxying .bit domains. Thus the use of something like FoxyProxy which chooses proxies by RegEx or String is nessecary if you still want to browse ICANN Domains

Hope this helps.