Silicone sealant for casting insitu window draught seal

I've posted that I've done it in the past.

I used low-tack packing tape. As I could find no low-tack packing tape, I simply used ordinary packing tape, with the teenyist bit of cornflour applied to it. With 'Flora Buttery" over the top of it, as a release agent.

It's essentially impossible to get it very neat. If you can get to outside the window, then it may be possible to remove the excess in a neat manner. (white spirit soaked rags help lots)

Of course, for really rotten windows, just omit the tape...

Ive found a scalpel blade and peeling back excess is a great way to neaten silicone.

Yeah - it's not impossible, just really annoying, especially if perched up a ladder...

It may be faster in some cases to simply unscrew the window tops, after casting the large glob of silicone, and do it flat.

You have the technique about right, it is common sense.

The release agent I used was candle wax. Just rub a candle on the bits where non-sticking contact was required.

In the original thread you recall, many agents were recommended as you remembered.

Ther comments were the use of masking tape to cover bits where you didn't want the sealant to wander to.