I use a mesh bag and use a combo of travel containers and shampoo/ conditioner for swimmers that come in containers that aren’t too big.
I try to make sure everything is closed tight at the end of my shower and wipe it off with my towel before putting away.

Travel size bottles (refill as needed) in a gallon ziploc. Dry the bottles with your towel before putting back in bag. Leave bag open at home to fully dry out.

Don’t shower but when did got travel sized and refilled them.

When traveling, I’ve found that the only containers that don’t leak are the disposable, travel-sized toiletries sold by the manufacturer (e.g. mini Pantene bottles). Even then, I put in a plastic bag or washable cosmetic bag. I’ve tried filling the reusable travel-size containers and they leak, so unfortunately, best to use the travel size of the brand. Some swim shampoo brands sell mini sizes.

Bottles designed for travel should not leak: pour into those. Dry them off with your towel after you shower and put them into a small, cheap cosmetic bag that you can wash every now and then. I would not carry a hairdryer or anything like that unless I had to go straight to work, just a wet brush or wide-toothed comb.

May I ask how do you carry shampoo & body wash to changing room shower after swim? Plastic shower caddy or a plastic bag or mesh bag? Do you carry full size or trial size bottles? How about hair dryer?

I am asking because it has been a mess that I carry those full size shampoo and body wash in a plastic grocery bag the last few times. They leaked everywhere inside the bag and the bag is wet after shower dripping everywhere. I think I must have done something wrong