I love the stuff........ but then again, I can't get hold of crabshell meal, so it's my only real source of chitin. I use it in my soil mixes and for topdressing, I'll also put a tablespoon full in my compost tea with my wormcastings.
I've never done the soaking/straining to make a tea for root drench or foliar so I couldn't help you there. I'd imagine it could make a great tea on its own just bubbling it in clean water. I do know it's got all the macro and micro nutients covered and is full of beneficial bacteria and a more readily available source of chitin than crabshell. A lot of people believe it is just insect shit. It is and it isn't. Its also got millions of minute particles of the mealworm exoskeletons shed during growth and then partly chewed into tiny fragments, this is the chitin source.