I'd actually agree with insides on domestic, I avoid normal domestic insides, the outsides are more profitable & a lot less hassle. However, I have to clean insides on hotels, stately homes etc but this is priced into work appropriately. Wagtail flippers are the best thing since sliced bread for insides. 
At one time when we were short of work we promoted in door cleans and gutter clearing. We now shy away from them and no longer promote this aspect of our business.
We originally erroneously thought that indoor cleans would be a way of earning during inclement weather but that never worked in practice.
Whilst cleaning a conservatory roof is passable in wet weather, emptying gutters isn't pleasant and is more dangerous due to wet ladder rungs. So the best time to clear gutters is when it is dry, which also happens to be the time when it's best to clean windows.
As per Vin's experience, we now earn more doing a normal window clean than doing internals so it just doesn't make financial sense to do it.
