I don't use After Run any more.

I moved over to using WD40.

I use it all the time especially now with humidity on the rise since it is summer time.
The WD40 will coat everything inside and helps to repel moisture.
Just a little down the carb and I pull out the plug and a lil down there.
As for blowing plugs---that may be the casr with cheap ones.
I do not have this problem with plugs and WD40.
Besides I would prefer to burn up a plug than loose a motor over poor maint IMO.

Now I use the MM in the motor for long period storage but I pull the motor, clean it up real good, then I put it in a plastic bag and I drench it in MMO.
I also try to get as much air out of the bag as possible and triple bag it. Just for leaks from the bag.

This is what I do but you will find everybody has their own way of doing things.