As we all know, gold doesn’t sticks to magnets. A moving gold particle can, however, be slowed as well as accelerated using a strong permanent magnet. You can take one of them, fix it above an open empty bottle, and submerge it into a fast, gold carrying stream of water.
The induced electrical current inside a gold particle is the cause of the force between the magnet and the gold particle, so its direction can be changed this way and it will more likely go into the bottle bellow.
All you need to do is pick up and empty the traps you have installed, just like every trapper does.
In reality, the shape of a bottle-magnets system must be quite complicated to be very useful, but the point is that this way, Lenz’s principle can indeed collect gold for you.