Yes any grey water is ok but not if it has bleach in it. Bath or shower water is fine too. If taking a shower put a bucket in there with u then water the garden with it.

I would be wary of dishwasher water, though, unless the tablets you use in the machine are eco-friendly.

I had just logged on to ask exactly the same Question!

Although I should have know the answer as just remembered that my mum has a large garden trug in her shower which she stands in.

Gardener's Question time last Sunday: advice was - fine if you use eco products for washing up liquid and in the shower, not great if you don't, best used on the ground, spread around, not in pots, don't concentrate on one area by regularly dumping it in the same spot.

Also don't under any circumstances use water with anti-bacterial soap in it or you'll risk destroying your entire soil ecosystem. Any vegetable based washing up liquid (like Ecover etc) will be fine.