Here's a picture of some seedlings started in
Canna Coco. The coco was not fed any nutrition.
As you can clearly see, the pre-charge already present in
Canna Coco can be far too much for many young seedlings.
I will never start seeds in unwashed coco. There's just no reason for it. Generally speakoping you only need to flush out a very small fraction of coco. In this case I didn't need more than 1 gallon of coco and it took me only a moment to rinse once I was able to recognize the issue.
The entire concept that you, as a new grower, cannot figure out how to charge your coco is misguided. Seedlings don't need much, if any, nutrition early on. I find that as the plants require feeding, and I feed them coco nutrients, the coco does a fine job of establishing the Cation bank and the CEC of the media.
Takes 1 minute, gives me peace of mind, and my seedlings don't look like this anymore.
So yeah. I'd flush the shit out of Canna if you ever caught me using the stuff again. Pictures=Experiences. Words=Heresay. You are smart enough to make up your own mind on the matter, I am certain.