I have to agree, you have to remove all foreign matter, that is, not just the weird plastic/silicone-like top but also any tiny ‘cyst-like’ content (your ‘plugs’ ?), PLUS the linear growth from all around the circumference of the lesion, plus any overspill of this lesion ‘edge’ that’s spreading out laterally over your skin – then it will appear to heal. Generally, while ever there is foreign matter in the lesion, it will hurt but once removed, it doesn’t hurt anymore, even though it’s ‘open’ and will begin to heal over. Even then, it doesn’t go back to looking like normal skin, it will be more pink or more white and it may still become ‘active’ again at some future time.
So far, I’ve found the best treatment is to ‘dry’ out the top with concealer and pressed powder, applied liberally – you have to completely fill the tiny hole in the middle and the whole of the periphery, or it won’t work. I’ve also found you have to do both applications to each lesion in turn, otherwise it simply melts the concealer! If you’re successful, the top eventually easily sloughs off (as it doesn’t develop all those spikes behind it, which normally anchor it).
I find anything else, like fungal or gel-type treatments just ‘melt’ the tops of the lesions, enabling the contents to spill out, or be spread out, encouraging new sores. This condition has to be the weirdest thing I’ve had, it’s like something from the X Files!