rpms should go up when A/C cuts on...however, you should not have a fluxuation in rpm...like 500 to 2000 to 500 to 2000 to 500....you get my drift. that revving is usually the IACV not doing its job. Yes you can damage one by "cleaning it" with carb cleaner or brake cleaner. most of those are very caustic chemicals and as such damage the weak diaphragm inside the IACV. They only way to know for sure if it is the IACV is to replace it. They can be pretty pricey though.