Reminds me of an anecdote from the driver of the council "soup tanker" when chemical toilets were still common. The local council had invested in a high tech lorry that had the facility to tip pails of toilet waste into a hopper that was then sucked into the tanker. When full the load would be transported to a treatment works and the sh1t blown into the works feed tanks.
The lorry had the added facility that large bore hoses could be used to attend blocked drains, couple to a blocked pipe via a manhole and suck the blockage clear.
There was a 3 storey block of flats which had occupied the drain suction team for several Saturday mornings. Finally they were sent yet again, coupled up, sucked, there was a dribble, sucked again, another dribble etc. The gang lost patience and back-blew at 30 psi. Result fountains in every bathroom on all 3 floors! The operation must have sorted the problem as the residents never complained of toilet blockages again.