Simplest way is to figure out the percentage of Earth-normal gravity for each planet.
Use 100 pennies in your Earth can - and the correct proportion for anywhere else. He suggests using plaster of Paris to put in the cans. He also warns not to put the stuff in a sink as it will clog the drain. Fill the Jupiter can and measure its mass after the stuff hardens. Penny-weights have varied over time due to specific metal content, so I just calculate the mass of pennies needed per can and adjust the mass with bits of paper thrown in.