I'd agree that washing the next day isn't ideal but it's better than not at all; the point is you're preventing build up if not keeping the engine scrupulously clean. We typically have a very quiet period around the handover between the day and night shifts where the engines are cool enough 99% of the time.
I don't know of any manufacturer that allows a wash without a dry, typically no more than 1 - 2 hours later.