I'm kind of afraid to answer this question because if I were to give you advice and it were to go badly, you would blame me, so I will not give you advice. Instead I will simply relate a true story.
Do not take this story as advice. Proceed at your own risk. I disavow any and all responsibility for any actions you may choose to take.
I own three ZhanChis. My first was a stickerless one. It was my first speed cube, and I was very impressed with it. I lubricated it with Traxxas 50k and it was good. Then something happened that resulted in it being unclean. I forget exactly what it was, but I probably dropped it on the floor or something. Being a bit of a germ-phobe, I have 91% isopropyl alcohol on hand all the time, and I tried to sterilize the exterior of the cube with a little of it on a tissue, but some of the alcohol evidently got inside. It apparently cut through the lubricant and did something to the surface of the plastic on the bearing surfaces because the friction went way, WAY up. The cube became hard to turn for a while, and I was afraid I had ruined it, but I kept using it, and eventually the alcohol evaporated and the lubricant started to work again, although some had been washed away by the alcohol.
I found this intriguing, and so I decided to make a project cube. I bought a new ZhanChi, a DIY white one, and I tried repeating the process in earnest. First I tried the cube as-is and compared it to the stickerless one, and it seemed far more bumpy when turning than the stickerless one, far from buttery smooth. I then sprinkled a little 91% isopropyl alcohol directly on top of the cube, maybe a half-teaspoon of it, letting it seep down inside. Then I started turning it, working the alcohol onto all the bearing surfaces, and it was exceedingly hard to turn, like sandpaper rubbing on sandpaper. I kept scrambling it and solving it, scrambling it and solving it, until the alcohol evaporated and the lubricant started to work again. My hands and arms hurt from the exertion because it was so hard to make it move, but I kept going. Plastic dust would fall out of the cube as if I was turning a pepper mill. I was breaking the cube in at a greatly accelerated rate, permanently altering the shape of the pieces.
When it was dry, I stopped and disassembled it and cleaned all the dust and gunk out of the cube, and then reassembled it and re-lubricated it. It became my main after that, and it was for a long time until I got a stickerless WeiLong V2, as I prefer the tactile feel of stickerless cubes and I prefer MoYu's stickerless colors to Dayan's. To this day, my white ZhanChi remains a very good cube, with no bumpy feel while turning. It never corner-twists and never pops, as the tensions are very tight, but it is far different from how it was when it was new. My experimental break-in process was an endurance trial for my hand and wrist muscles, and I don't know what the long-term effects will be on the plastic, but the result was a very quiet, very smooth ZhanChi with which I have no complaints.
I repeat: Do not take this story as advice. Proceed at your own risk. I disavow any and all responsibility for any actions you may choose to take.