bathtub tape instead of caulking

[gabagoo]

This is not really a plumbing question but after looking over the forum headings this seemed to be the place to post. Sorry if I put it in the wrong spot.

In any case a friend was telling me that they now sell this tape that is used in tubs instead of using caulking or Dap. I bought some and it looked like a good idea until I started using it. First off I spent a good hour removing all the old caulking and cleaned it all up as good as could be expected. This tape is really a piece of plastic that can bend in the midddle and has tape on the back. I followed the instructions and installed it. I found that it did not seem to stick to well and figured it needed time to cure. The next day I inspected the tape and I pushed on it in a few places and could clearly see the part that lay on the tub would lift slightly and the parts that hit the grout in between the tiles was not sticking at all so I force id down and left it again. A few hours later I checked it again and it still made me feel uncomfortable that this stuff was not going to allow water to get underneath it, so I went and bought some dap to put on above and below the tape as a backup which completely negated buying the stuff in the first place.
has anyone else here tried this stuff before with any success?

[Redwood]

I use caulk cause it works.

[OTM Doc]

Why not use grout, clean the surface after scraping out the old grout and caulk. fill the tub with water. Pack in the grout and let it sit 24 hours. Then drain the water out of the tub. Filling the tub with water allows for the tub to settle and not pull away from the grout as it will do if you grout the tub empty.

[pushkins]

Grout will crack, the tub will expand and contract and a hugely different rate to the tile, this will cause cracking in the grout. Grout has zero flexibility, this isn't an "if" it's a "when".

[Kman]

Agree with the above statement.

Silicone is the longest lasting sealant you can use, however in horizontal applications it has a tendency to trap water. Sometimes mold will build up behind it.

I've used that tape once, many years ago, and will never use it again. Even in the best conditions with a flat clean surface, you're using tape to stop water. Won't work.

The best course of action is to use a good quality caulk that is made for bath & kitchen (not painter's caulk), clean the area thoroughly and let it dry, apply the caulk and let it dry for at least a day before using the tub. Unfortunately, due to the soaps and oils in combination with the minerals in hard water, this is a job that requires redoing every two or three years.

[Redwood]

My preference is Polyseamseal.