Never done it before in all the time melting lead in a pot (since about 1998). I have always used a slotted spoon and just dredged out the clips and dross after fluxing. I tried it today and it worked very well. It is a Craftsman telescoping type magnet that is very strong. The only disadvantage I saw was that sometimes the clips would smack together when the magnet made contact and it would fling dross and lead spatter. I was wearing eye pro and pants, gloves, lace up shoes etc. so I was squared away. I then skimmed off the rust and dross with the spoon and poured out my ingots.
It has been over 2 years since I cast and smelted wheel weights so it was nice to start building up my stores again.