Hey Dank
Happy to know you’re dabbling with hydro bro.
I’ve never used coco in bricks before but have run at least 8 different brands over the years and have never rinsed any of it.
I do saturate my coco with about 650 ppm of a basic N-P-K set at 6.0 and some other goodies but that’s about it.
Your Jiffy’s will work fine but I always start my seedlings in a Grodan 1.5” rockwool starter cube then drop that into a Grodan 4x4” cube after the seeding pops its head out. After I see roots coming through the bottom of the 4x4” about 10 days later I set the cube on a bed of coco/perlite or more rockwool. The 4x4” cubes will give you extra veg time and they don’t take up much space.
I fertigate with 350PPM once a day for the first week with a turkey baster and then bump them up to 600PPM by day 10. On day 21 I put them on automated fertigation and feed 3-5 times a day for 5 minutes with no emitters on my feed lines.