Remove Slice Views (Compare1, ...) from scene

Hi,
I switched the layout to Compare grid briefly and thus created a whole lot of additional Slice views (Compare1 thru Compare9). Even after going back into other layout options, these slice views are still around in the background and clutter the “View controllers” module. Is there a way to remove some of them (I would be fine with just having one additional slice view besides the classic red, green, yellow ones)?
Thank you
Stephan