*I will be safe rather than sorry when I mix mine up.
If it is not something you have ever done, and don't have the proper PPE, don't do it. If you have access to a radiator shop, have them do it.
If you are determined to experiment, start with a 25 percent mix of the muriatic you can find at Home Depot and clean water. ALWAYS ADD ACID TO WATER - not the other way around. Wear a full face shield, rubber apron and long chemical gloves. The fumes will wreck your lungs and a single drop in your eyes can blind you. I am not trying to sound like Chicken Little but if you don't have any experience doing this sort of thing you can hurt yourself very badly and destroy everything near where you are working. The fumes are very corrosive.
A very good way to learn how strong, how long, and how effective, is to take a couple of old rusty steel bolts and put them in a plastic bucket with a gallon or so of 25 percent mix. Watch what happens in how long and what they look like at different periods of soaking. See what effect oil and dirt has on the process. Spend the time to learn how the stuff works. Some things you can leave in overnight, some things you want to pull out after a few minutes. Temperaturature effects the process a great deal.
I use this method to salvage stuff that looks really bad and use it to prepare parts for painting and re-use. I think it is the fastest way to go but it is not without risk.
Do it outdoors, stay upwind of the bucket, wear PPE, and keep another bucket of water and baking soda nearby to neutralize the parts. Keep a garden hose within reach to wash off spills and your body. Don't wear any clothing you don't mind throwing away later.
It is not like playing with dynamite but be careful. Chemical burns are horrible.