Go for hooded towel ponchos in age 4-5, or the Jojo maman Bebe hooded dressing gowns made from towelling material are lovely (had two bargain ones from vinted).
We use giant muslin
We bought the kids hooded towels from IKEA and my daughter loves them. We have the fox and shark one.
We just use our adult towels
Once she outgrew the baby towels we just started using ours
I just use a normal bath towel, a bright pink one for my little boy 🤣 wraps him up nice and cosy x