Ah....., I see you are talking about the permanent ablution block at the entrance to MB. Admittedly they are a bit long in the tooth and suffer from a lack of decent ventilation, but I can tell you that the 'facilities' at all campsites, and those at the circuit, have improved a hundredfold compared with what they were 20 years and more ago.
I remember going to use a loo on the circuit when....... no, I won't say, you might bring up your dinner/breakfast/lunch or all three.
And as far as Mr Brown's description of the facilities on HA, the only word of truth was 'pile', and there's lots of them
Del