"Do not recommend" simple says that there is no recommendation from them to do so. The phrase actually does not mean "they recommend against it." Of course, Ilford does recommend against it, and I've also read that and cheerfully disregarded it in favor of Jobo's alternate recommendation for a presoak with rotary processing, ever since I got my Jobo in 1996 or so. Unless I start seeing problems I can attribute to it I will continue doing so.
Originally Posted by Gerald C Koch
"Start with the manufacturer's instructions" may be fine as a starting point (but not absolute laws) but when the film maker says one thing and the processor maker says another, some experimentation is in order.