Well with canned beans just rinsing them would work to reduce gas. They contain something called raffinose which is essentially 3 types of sugar (galactose, glucose & fructose) bound together, which is hard for humans to digest. Rinsing removes most of it, and reduces gas.
The soaking would be for dried beans, you soak them for a day, get rid of the water, rinse, cook, and rinse after cooking them too. More work, but dry beans are one of the cheapest nutrient dense foods even if it's partial protein (missing methionine and tryptophan).