I’d guess for trout, the best bet would be to go as natural as possible. That being said, dried salted eggs aren’t going to be real natural ( in feel anyway) might try to look into something that will cure them and also keep them soft and cause them to milk well. If you start getting into salmon fishing, be prepared to buy all kinds of different cures and scents because salmons scent preferences can change by the hour! I know your method you mentioned will work well for steelhead. The thing with roe is you can have something that looks great and not catch anything on it while the guy next to you can appear to have the exact same bait and will be pounding fish literally every cast because he tweaked something somewhere and that’s where you end up having 5 different kinds of baits with you every time you go out...
I know you mentioned not buying commercial cure but just know that those cures can take a lot of guess work out of the process and they can help you catch a lot of fish.