I guess it depends on why you are emptying the loop in the first place too.
I mean, if you are emptying it to change the colour of coolant, then you could simply empty the loop (without blowing in the tubes), do a run in the loop with distilled water to clean out as much muck as you can, drain it, then do a run with the new coolant, drain it, and then fill it as you normally would with the new coolant. Note, in all this you NEVER NEED to blow into the tubes, because you are using the distilled water and coolant to do the clean out for you.
If you are simply emptying to do your yearly/half yearly/whatever maintenance, and you intend on using the same coolant, then you probably don't care so much about clearing out as much coolant as possible anyway, since whatever is left in the res will get cleaned, when you clean that.
The big thing to take away though, is that you want to be careful not to get water on your precious hardware, (or on your wifes precious carpet LOL), so just make sure you do your due diligence.
And Remmy is right, you don't want to introduce contaminants into your cooling system unless you are very sure that your biocide/silver coil/whatever you are using to control algae is doing its job well. And even if it is, you still don't want to if you can avoid it.