Depending on the area you want to clean on the Eyecon, will determine best practices. You should use a clean cloth and rubbing alcohol or ammonia-based cleaning liquid. You can find more information here on cleaning your Eyecon.
Usually if the Eyecon is rocking it is because either the rubber foot isn’t stretched over the bottom of one or more of the legs OR a leg has become unscrewed slightly. Please check both of those first. If it is still rocking, then perhaps the counter is not level and you could unscrew the leg to adjust for that.