others may disagree, but i had some bark "mulcjing" looked marvelous for the first month after that, nah.
The problems i encountered were as follows, "new bark" wet and dark (looked great) but as it got older and dried out it shrank, also it then "dissappeared" into the soil
I would suggest, you dig out an area of at least 6 inches in depth, put down a "weed fabric" and cover the lot in bark, then wait and and more as required.
only thing is the bark, as you can get "play pit sand" which has been washed, i am not sure if you can get "play bark" as we also noticed "little things with legs" in our bark, no problem for plants, and NOT lots of them, but we did see them.