I need advice...

This is a long story...our vet suggested that we start house training our 3 GDs because our deaf one, Lilly, has major OCD issues with chewing up her tail while she was in her crate. We did everything to try to correct the problem with leaving the proper chew toys and bones in her crate, but it did not help with keeping her away from her tail.

So we blocked off a small section of the house with pet gates (our dining room and hallway are now the dog's den/play area) to see how they respond.

Here is their response:
- tearing up the blinds (expected and be replaced)
- tearing up a part carpet (expected and we had plans to replace in the future)
- chewing up 2 inches out of our 4 inch Window Sill
- chewing up our wood side panels along the room and hallway (we noticed the trend at the corners of the room/hallway, but now their are scratches and chewing in the middle of the panel too)
- tearing up and chewing the fitted sheet on their twin mattress (aka their bed).
- Licking the walls...(every dog does this right?)

Here have been our responses:
- Spraying the entire area with Bitter Spray...no good. they loved the taste so much they chewed on the areas more. I shouldve known bitter apple wasnt going to work because they ate a bag of chips flavored... Limon. We would try the pepper, but we have caught the dogs licking the bottle of hot sauce.
- Block off the Sill with their crates
- No more sheets on the bed
- Putting a runner over the torn up part of the carpet
- Instead of 2 walks plus dog park, we know have 4 walks plus dog walks throughout the week!

The major problem was chewing until last night. We went out to dinner for less than a hour at a local Mexican joint...and came back to a HOLE IN THE WALL. Not a typical at the bottom of the room like someone kicked it, but in the freaking MIDDLE OF THE DARN WALL! The worst part was the hole was big enough for me to stick my head through (4X4?)! Now I love my dogs, but Jorge (the bf and joint owner of our home) was PISSED TO THE MAX.

All three dogs had a part in that mess because their noses were all white and they were obviously chewing on it.

So now I have a problem of chewing and making holes in the wall.

Advice anyone? I was going to be ghetto and go to Home Depot and buy metal siding to protect the panels from more chewing, but I would love more insight and advice on what to do.

Thanks in advance!
Tayyaba