Steve’s nest boxes

Hi all, well the activity on our feeders is frantic, and there are so many species coming to the feeders now, I’ve lost count of the species and numbers but, blue tits are a regular visitor and in large gangs!

So, no shortage of birds but, one of my boxes has had a resident rooster, right from the real cold weather until present, or possibly two different birds? Anyway, it’s a blue tit, it comes home around 5 in the evening, and goes off around 6-30 in the morning. The bird is still using the box as a toilet too.
This happened before, a bird would roost, and use the toilet, then leave in the morning, then mid morning, another bird, or possibly the same one would appear, and clean the toilet out.

Now, the tennant is sleeping, and using the toilet but, no birds are cleaning up, and who could blame them lol! So, the box is quite dirty, the other box which is quite a bit further away, doesn’t seem to attract anything so far? I am hopeful though.
Anyway, should I leave the dirty box at this stage and time of year, or just quickly clean it out? I’m concerned that the mess may be putting off a courting couple?

Any opinions or advice?

Here’s a pic of the dirty box, and one of the cleaner des res





Thanks
Steve