When is it better to think without words?

I have used this "loading the subconscious" technique for many years, basically juggling a coarse mental image of data flows, and potential data structures, however I don't find it to be "free labour".

(I view this as a purely mental variation on the way I manage so solve various physical 3d puzzles. For those I tend to simply rotate and play with the puzzles, loosely observing, but not concentrating. Eventually an insight arises.)

I find it has a cost, and that is in terms of poor and disturbed sleep. If used too much for too long, I get quite exhausted and run down.

So I have found it is best to do in small batches, or to simply hold in reserve for when has an really knotty problem to solve.