I always keep a tin of Chappie in for upset tums as well.
Yes, this is our standby as well. We keep a tin or two in the back of the fridge "just in case"

.
You may find that one meal a day could cause some problems especially a bit of morning sickness. A small amount of food or a treat just before bedtime is usually recommended so that they have something to digest overnight.
Have to agree with its.sme, at eight months Archie should really have his daily food allowance split between two meals. Chicken or flaked white fish and rice is one of the staple recovery diets for cockers and, in my opinion, is just as good if not better than many of the rather expensive foods that are available from your vets.
Hope young Archie is soon feeling better and can be persuaded to move away from his plastic diet

.
Bob.