Yes this is how it's done. As stated above it's called a snap test.
(Kind of like, "oh snap, you want me to do what?)
All modern throttle by wire engines are safe at WOT. You can actually put it to the floor and let it bounce of the rev limiter on gasoline engines and on diesels it will just pull fuel and rev to the limit. That's why on most engines there is no longer a red line on the tach. No reason for it anymore.
And for those of you that are gloating about no smog test in your state. You won't gloat for long. Your gloating is almost over. :B