Where did this come from?
If it were me, I'd go through a dry run every time I got into the airplane with a parachute on, just like I did every time I got in my hang gliding harness. Read this:
https://www.parachuteshop.com
/Emergency%20Parachutes%20WHAT%20EVERY%20PILOT%20NEEDS%20TO%20KNOW.htm
Once you're made the determination that the airplane you are flying is no longer airworthy, what are you going to do? First off, jettison the door or canopy. Next, brace yourself to get out the door, and release your harness, then push yourself out the door and as soon as you are clear of the airplane, look down to where the D ring should be, grab it and pull as if your life depends on it, NOW!
If you get the parachute deployed immediately, it doesn't matter, whatever happens is better than not pulling. Remember, this is an emergency parachute, it is meant to open quickly at relatively low rates of descent. You do not want to wait until you have reached a high rate of descent, as the opening shock may kill you.
As long as we are doing analogies, here's one: Ships carry lifeboats for a reason. Is the lifeboat a more seaworthy craft than an intact ship? No, it is not. It is preferable to a sinking ship, however, which is why people get into them. Same deal here. Leaving the airplane is a desperate measure, you'd only do it if you thought you could not land successfully. Everyone who has done this and survived has said the same thing, that getting out of the airplane is the hard part. Operating a round parachute is not a difficult task. Way back when I did my first jumps, they started us on static line, then on to hop n pops. Some of us messed up our first hop n pops pretty badly, but everyone survived, because a deployment at a low rate of descent is fairly forgiving. Blowing a deployment while you are at terminal velocity, which in a stable arch is around 10,000 fpm worth of descent, is not nearly as forgiving.
From the Softie emergency parachute's operator's manual:
Once you have exited the aircraft, you will most likely be tumbling.
The most important thing to do is pull the ripcord immediately and throw it away. It takes approximately 2-3 seconds for the parachute to fully deploy. Altitude used for complete deployment at terminal velocity is approximately 300-500 feet. That is not the altitude to initiate emergency procedures, but the distance required for deployment and opening.
Skydiving schools teach skydiving. They have a vested interest in not having people die unnecessarily. Accordingly, they aren't going to let you jump your single, no reserve, no AAD emergency parachute at all, trained or not. You do know that skydivers do expect to use their reserves every 500 - 1000 jumps, don't you? The only reason to use your emergency parachute is that you will die if you stay in the airplane. It's not a foolproof system, but it's better than no system at all.
If you really wanted to practice something useful, you'd need to practice exits. I'm not sure how to simulate an out of control airplane, which is what you'd need to do this effectively.
If you do decide to take up aerobatics and decide to use a skydiver's rig as your parachute system, make sure you stay high. Skydiving rigs take a while to open since they are designed to open slowly enough to not kill you with the opening shock.
