I am sure that I don't have as much experience as most of you, I use spirals almost exclusively even with the problem of inserting them into the blade holders.  I secure the bottom of the blade first since it's the most difficult,  Then I feed it up through the workpiece.  Next, the top...and while this can be a bit tricky, with a bit of practice you'll soon get the hang of it.  The blade can be turned/twisted with the fingertips alone--you don't need the pliers to turn it--just enough to align it so that it inserts into the top blade holder as if it were any other flat blade.  I know many of you will say it can't be done that way, but I have had plenty of practice with this method.  It does work.