A possible solution that I'm employing while learning myself as well as teaching others is to stop using the smooth breathing at all.
EDIT: Hey there;) So to respond to your questions in comments:
I don't know of any materials that would use this convention so far, but I plan to change that. Personally I know a few people, that have adopted it, and I wasn't even the first. One of the teachers at AVN (with very good mastery of AG) uses it, likewise I also met some academic from Britain doing the same (can't give the specifics, as I think I should ask for permission first, since they don't publish on their own so far, and so it is not a widely known fact).
Just as you assumed, Joonas, smooth breathing is recognized by the absence of a breathing mark. Since that with utmost probability it wasn't pronounced in any way, there's no point in preserving it, and if it proves otherwise sometime in the future - we can adopt.
I've used the convention in all the materials I'm preparing for my students, and the main reason is that I noticed on quite a large scale (100+ people), that it at most confuses students, if anything, especially at the beginning, when there are more important aspects of the language and its alphabet to draw their attention.
As for the technique - for every text, that I have available in editable format I just apply a few letter swaps before proceeding to read it or use it in class.