How do I clear all spamfilter words from my channel?

Answer 1

First /mode #channel g

that will show up what is on the channel filter, then you can /mode channel -g "spamfilter"

For example " idiot " on the spam-filter

you need to type  /mode #channel -g idiot

Answer 2

If you have founder access to a channel you can also use chanserv to remove all them once:

/cs clear #channel bans g