If your going to keep using your tub, a few times a week you should just encourage him into the tub, and give him lots of treats. Then set him free.lol. Soon enough he will associate the tub with good things. Once he's comfortable, you can try turning the water on (dont get him wet, unless the water is just running on his feet) and give him some treats. And then, set him free. Each time he seems to be ok with a step, move forward by turning the water on, and just rubbing his back with your hands (dry, dont wet them).
I had to do this with my youngest GSD. I tried giving him a bath once and ended up IN the tub with him, and the glass shower doors closed so he couldnt escape. That was not working out for him OR me, so i decided to just start slow, and get him used to being in the tub chillen out, then adding the running water, then just giving him some booty scratches while the water was on, and now when i say its *bathtime* they dont mind going in because they know its a good thing.
Also, like some others here have said, the after bath *tug* game with the towel is their favorite part. So maybe when your done working with him in the tub, you could try playing a quick game of tug with an old towel. (try to rub him with it as if you were drying him) but keep it fun and playful. Then he'll know he has to deal with the bath, but knows playtime with you is right around the corner!
My dogs are the hose police, if they see me even walk towards it they bark and get all excited. Then they attack the hose, so i doubt an outdoor bath would work in my favor! LOL
If he's still small enough, try bathing him in the kitchen sink. I gave mine two baths in the sink before they were too big to fit anymore.
Sometimes it just takes time. At first mine would struggle and complain, but eventually they learned to love baths. We take them to a self serve place where we rent a tub for $11.00 per dog, and usually do them about every month or two. It's at the off leash park we go to, and they're usually still off leash when we get to the building, and they go right in a pick out their own tub.
Sometimes it's the SAME tub, lol!
We bathed them last weekend, and there was a guy browsing in the area right next to the tubs (they sell collars, leashes, toys, treats, etc.), and he was amazed by how enthusiastic Dena & Keefer are about baths. He commented "wow, they just jumped right in the tub on their own - that's so cool!"
But they weren't always like that, it took time. I like the elevated tubs at Mudpuppy's because I don't need to lean over, they're small enough that the dog can't move around a lot, and they have a neck strap that can be clipped into the wall. It's a lot harder to contain a dog in a large bathtub unless they're REALLY cooperative.
I have to admitt Sarge goes to the groomer for his bath, ear clean,and nail trim.
But they say he does really well and they all like him!!
I went to pick him up one day and he wasnt quite done. The man saw me come in and said, listen...would mind waitting outside. I just have to trim his nails and we do it in this area over here. hes very easy to handle but if he sees you...ITS ALL OVER!!!
So I went outside until he was finished. When sarge sees me he knows its a ride in the jeep and a trip to mcdonalds so he gets pretty excited.
My dogs would tolerate baths - not thrilled, but would stay put until released. Then I installed one of the long hoses with a hand held shower head and for some reason they like that set up.
I have a shower they can step into and I always use the massage setting on the shower head on them. They seem to be really relaxed and even step into the shower on their own. Less water all over the bathroom, too!