There's also a guy sat on the pier at Balamb harbour who will not play with any special rules at all. Playing against him will automatically clear all the rules you currently carry, meaning you can't spread anything, though at one point in the game he suddenly disappears... I think it's when you defeat all the CC Group members, but I'm still not sure.

Also, I find that not being in possession of any new rules when in any area tends to make it randomly abolish them (though as that guide mentions, rule removal is rare). This is kinda useful to know in Lunar Base where every single rule is used, so you can keep challenging (and resetting the game) until Random gets removed.