I'm also going to HEAVILY urge you to try GM Silicone Emulsion. EXCELLENT PRODUCT!! I usually just grab some on my finger and apply it that way vs. using the little applicator thing which can be difficult to spread product with in tight spots. You can also use Meguiars #40 vinyl/rubber cleaner/conditioner, however the GM stuff lasts a considerably longer. Typically one can expect to have to apply the GM silicone emulsion 4-6 times per year, or monthly depending on how fast the weather-stripping dries out (this is a weather/climate related issue).
Its fairly inexpensive as well and can be purchased a ANY GM Dealership. (I think its like 2 or 3 dollars??)
If you happen to get a bit of excess product on the paint, it should clean off fairly easily. If that ever happens, I usually just take some Quik Detailer and a microfiber cloth to clean the excess emulsion off the paint.