I did consider the bag with magnets method but in the end decided to upgrade to fermzilla in part to do pressure fermentation and dry hop using the collection jar. When I was talking through with my mate who brews commercially he felt that the hops would degrade a fair bit sitting in the fermentor during high krasuen etc so just fermzilla seemed the ideal route
I have a carb cap on one side of the jar and cokecap on the other so pretty easy to purge. Same steps in terms of removing trub, then put hops in collection jar screw on, put gas on one side of collection jar and pressurise, slightly unscrew coke cap a few times to let oxygen out and keep refilling with gas. Then just open the valve and let the beer in.
I had a lot of hops in there and they stuck but I assumed they would gradually mix in, nearly a day later there was a big hop cake in the collection jar. So I pressurised the whole fermzilla, closed the BF valve, then depressurised the main chamber and opened the BF valve again. This nudged a few up but not the whole lot. I did a couple more times really slow progress.
Eventually just started doing the same thing but turned the fermzilla upside down in the stand to release the collection jar pressure and the combination of gravity and pressure meant they caved into the beer eventually. So 250g of dry hops all mixed in now
It’s one of those things where the next time I do a dry hop I will have learned my lesson and it will be easy. Just gotta get the pressures right etc
EDIT - But also meant to say, I do have a couple of stir bar magnets and next time will put in collection jar with dry hops so that if I do get a bit stuck I can just spin it round in there to dig them out