There's no command for it?

For example, WoW has the command /cancelaura used in macros.

My Paladin had a debuff wipe for when I tanked:

/cancelaura Divine Shield
/cast Divine Shield

Hit it twice. If buffs up, it removes it. If not, it casts it. Buffs and debuffs there are called "auras" by the client, despite buffs being the only ones you can cancel that way.

I had one for threat redirections too because of hunter/rogue trolling assholes as a healer.