Girls and boys, trouble! I backed up and lightly pressed against the plastic pillar. The bumper dented inward a little, a smooth hole the size of a fist formed. The paint didn't peel off, only a dirty stain remained. Is it possible to smooth this out without a paintbrush?

If the plastic hasn't burst and there are no sharp bends on the back, then the chances are very high. And is the bumper original or some kind of Chinese license? Because native plastic remembers its original shape much better.                   

Working with plastic is a pleasure, as it has the so-called thermal shape memory, so don't worry, your problem will be solved in just a few minutes. The master will first carefully heat the place of deformation with a technical hair dryer to a certain temperature to make the polymer elastic, and then with a special tool from the inside or a vacuum suction cup from the outside he will smoothly return it to its place, after which it will only be necessary to lightly polish the mark from the column. To make sure whether your case meets the criteria for such a quick recovery, see the detailed description of the technology https://autobodylab.com/services/pdr/, which clearly shows how similar defects are eliminated on various body elements. A huge plus of this method for plastic parts is that a thick layer of putty is not applied to them, which from vibrations or a slight push in the future could simply crack and fall off in pieces. Wash off the dirt, take a picture of the dent at an angle in good daylight, and feel free to send it to the masters in messenger for an accurate assessment - I'm sure the result will pleasantly surprise you and you won't regret the money spent!