Adding grain to wine to increase body, but how?

[Deltabrew]

I'm making some Victoria plum wine with 8kg of fruit. In his book CJJ Berry says it can be thin and to add a lb of grain, but that's about all.
So I got some Wheat malt, it's all chipped up in a bag and I poured some boiling water on to soften it and will leave it overnight.
Do I need to do anything else with it? (pound it, mash it?)
When do I add it, right at the start with the pectolase and campden tabs?

 

[Obadiah Boondoggle]

I agree - it's not a very helpful piece of advice from CJ Berry

Thin in what sense? Alcohol content, colour, mouth feel?

Adding boiling water to the grain will not increase alcohol content

I am a bit puzzled by the advice tbh