Frankly, I've all but given up on polysulfide (etc.) caulking. It just doesn't last and I've got enough to do without having to recaulk everything every 6-8 mos.
I've converted to Butyl rubber tape. Along the way I've discovered not all butyl tape is the same.
The more common black butyl 'window' tape seems to have a thicker, more firmer consistency. More like 'putty in a strip'. Someone once offered me some of their butyl tape they purchased at an R/V store just a couple years ago and it was all but dried out (R/V butyl is designed for roofing and it has a different solvent content).
Here is the 'marine grade' tape I have/am using now. It is nice & soft (almost gooey) and works easily. It's not as cheap as the more common variety but I've seen the difference and it's clearly worth the extra cost:
http://www.pbase.com/mainecruising/butyl_tape
Here is the article that converted me describing the how & why of using Butyl rubber tape over conventional caulking (polysulfides, etc.).
http://www.pbase.com/mainecruising/rebedding_hardware