Here's how I rank stopping power: Brakes, slowing down, skidding, skipping. I personally do not recommend skipping because of the 4 methods it is the least effective and the most likely to taco your wheel (when the wheel bangs the ground on impact).
But, skidding is soooOOOooo cool. Here's how you do it.
The physics of skidding:
Let's define:
static friction = the measure of opposing force that keeps the tire from sliding on the road whether the bike is rolling or not. This is a function of how hard they are pressed together (how much you weigh).
dynamic friction = the measure force opposing between the tire and the road after the sliding has started. This is a function of how hard they are pressed together (how much you weigh).
You are right, when you say "the limiting factor is leg strength". This is true for a lot of riders because they cannot create an amount of force greater than the static friction force. Transferring more force than that of static friction will "break" the coefficient of friction and change the state to dynamic friction, which requires less force to maintain. Beginners typically only use one leg as if with a coaster brake.
Force = Mass x Acceleration. That being said, if your wheel's mass is constant and you can decelerate (negative acceleration) your wheel fast enough, you can create MORE force than the Static Friction force and switch over to dynamic friction. Try using both legs by pushing down with the back leg and pulling up with the front leg (can't do this with platforms).
But wait, boys and girls, there's more. You can lower the Static Friction force that you need to overcome by decreasing the force used in the binding of the two objects of the friction. Do this by shifting the weight off of your back wheel to the front by leaning forward or hop up (skipping).
This static and dynamic friction are determined by the two surfaces, the tire and the road. Hart tires, grass, wet roads, etc...will slide easier. Soft tires, porous roads, etc...will be harder to slide on.
So, if you want to skid, generate a lot of force, move weight off of the back wheel, and combine two surfaces that make little friction. It's that's simple.
Also, if you want to be invisible, just figure out a way for light to not bounce off of you.