o_Nightshade_o
I used to do that every time I tried to use vibrato. It's just something that you have to work through. I'm sure that experienced singers will do that if they need to add alot of it.
If you're an experienced singer, you don't 'need to add a lot of it,' you either have it or you don't, adding what you don't have is how you damage your voice. That's why there's different voice classifications - a Dramatic Soprano should not sing the role of Pamina, a Lyric Soprano role - that would be stupid - the voice would be much too heavy and the vibrato would be too thick, and trying to restrain it would only hurt the singer, and the reverse is true as well. A little soubrette isn't going to be singing a Wagnerian role - unless the casting director is on drugs. Trying to 'add a lot of vibrato' to that would obliterate the voice.
If you don't know what you're doing, you don't know what you're doing, but experienced singers - one would hope - do.