In Poland
Long time ago people figured this and started to invent lure retrievers. While searching the internet i found many different constructions of lure retrievers. I think all of them may by effective under certain conditions.
I personally use 3 types of lure retrievers. I always make them by myself because it is great fun for me :) I decided to show you how do they look and work.
1) This retriever is the most effective and it never destroys lure hooks or trebles. It has one disadvantage. You can use it only when you are straight over your lure stuck in stump. But when you are on a boat it is no problem. This retriever has for me 95% efficiency. When I am on a boat I use only this one.
How to make it?
You need some heavy peace of steel rod, pipe with lead inside or (like in my case) a wrench filled with lead. It should be about 10oz - 1lb heavy.
Next step is to fasten 2 quite big (in my case 2in in diameter) rings for the line.
How to use it?
Just like on a photo below. When you drop your retriever down the line fast it hits hook or lure and releases it. Sometimes it is necessary to hit your lure few times from different directions.
2) Second type is also very effective. We can use it when lure is far from us - for example when fishing for trout in river. To use this retriever it is necessary to use a strong snap swivel. Disadvantage in this case is destroying your hooks or trebles, but when you fish with expensive rapalas or Japanese lures i think it doesn't matter :)
I made 2 of this retrievers recently and I made some photos. I think they show good enough how to make this retriever. One important thing, when using it in fast rivers - use as thin retriever line as possible. It will be easier to reach your lure for a long distance. This retriever should by 3oz - 6oz heavy.
3) Third group. This retriever may be funny and silly for you, but it is THE BEST while fishing for trout in small rivers and streams. You can use it even when your lure is on a tree instead of water :)
I thing it is obvious how it works and how to do this :) You can use everything what is strong enough and catches hooks well.
Last month I regained a small crankbait after the line was snapped! I knew where exactly I lost my lure and I threw my retriever into the river just above this place. River stream moved it just to my lure and hooks caught a retrievers net.