i normally use a 12v bat charger set to 10a.. but you can use more or less ams as you have or with size of piece... more amps needed for faster action or larger work piece.
get a plastic tub or basin. put in some sacraficiam metal around the bottom and sides. electrolysis is line of site..so the more anodes the better. expanded metal... chicken wire.. etc. all works good.
run a wire connecting sides and bottom and out of the basin. hook + clamp to that.. put in some pvc pip couplers as risers to get your piece to be cleaned off the anodes. run a wire from that piece out of basin to - clamp.
if you get them backwards the pice you are working on will disolve...
mix water and sodium carbonate ( washing soda.. or more commonly.. pH+ fromt he pool section ).. about 1-2 cup per 5g of water. depends..
add watrer.. hookup charger and it will bubble.
do this outside. it will release hydrogen and oxygen gasses.
lastly... if you only have a small charger.. like a 1.5 amp job.. or a smart charger.
put a car batter out.. hookup the charger to that car battery and then your wires to that battery / charger comb.. usually works ok..