Firefighters spent 40 minutes rescuing a toddler with his leg stuck down a drain outside CMK Library on Monday.
And their secret tool was ... good old fashioned detergent.
The round manhole, which was about 10cm diameter, was missing a cover. It is on the pavement just a few metres away from the council's civic offices in Silbury Boulevard.
It is understood the boy was walking along the pavement when his leg disappeared down the hole.
"His whole leg was stuck, which was obviously distressing for him," said a Bucks fire spokesman.
A crew from Broughton feared at first they would have to dig up adjoining paving slabs to free the child.
"Then one of the firefighters managed to get his arm down the hole to check that the boy's foot was not at an awakward angle. After that they decided to use detergent to make the leg slippery enough to get free," siad the spokesman.
"Detergent is something that is carried as part of the kit on fire engines. It's usually used for decontamination purposes," he added.
Within minutes the tot was free, and firefighters gave first aid to grazes.
It is understood the boy needed minor first aid and a cuddle but was otherwise fine.
An ambulance attended the incident, which happened at 11.40am, but was not needed.
The dangerous drain has been reported to MK Council. It is not yet known whether they were aware of it before the incident.