See my post #6 above

I used to do this as part of a job I once had.

 

Nope. I drove it all day today and its been silent.

 

The creaky door seals on my 2013 ES350 were driving me crazy. I live in Canada.

After consulting the all-powerful oracle (aka Google), I went to my local Toyota dealership and purchased a can of Toyota Silicone Spray (part number C0009-10450). The description on the can says it is "excellent for treating and maintaining rubber door moldings".

1. I sprayed some Windex on a cloth, and wiped the seals clean.
2. I sprayed some Silicone Spray on another cloth, and carefully wiped the seals with it.

Result: one very quiet, completely creak- and squeak-free car.

This fix was as effective as, and much cheaper than, that available with some of the fancy products out there. Even better, I used a Toyota item.