I find this quite useful when tweaking and testing my spells, particularly the ones with On Activate logic. When creating a spell, just add an On Message Received block along these lines:
The message text you use is, of course, up to you. I'd recommend using something else if you plan to use your spell competitively. The or block is optional, and just allows dispelling that spell specifically.
The actual Dispel spell looks like this:
Of course a wider ranged broadcast can also be used, but I find this works alright so far for me.
This is probably a point so basic it's not worth mentioning among vets, but perhaps it will make things a bit easier for my fellow neophytes.