maybe use a toothbrush with hard bristles instead. good enough to get into the small spaces andget the dirt out with less chance to break something

the thing is, yeah, if your button is so gunked up that you can't really click it anymore, cleaning certainly is a good way to start, but most of the time, the unresponsive button problem is caused by the buttons contact getting dirty and thus unresponsive as the signal doesn't always make it through anymore. blowing into it adds humidity meaning its easier to close the circuit and get the signal through. however, the humidity eventually causes more gunk making it worse in the long run.

 

Probably fine as a temp fix but I wouldn't trust it long term. This and this should help although if it was me I'd be soldering some new switches in/getting someone else to do it.

 

I was thinking more on the topic of dirt, if you get a can of compressed air you could use it to clean your shoulder buttons (albeit not as thoroughly.) Blowing into the button can help, but the enzymes in our saliva degrade the hardware over time; not to mention all the gunk that is also attracted.