[Goosegirl]

I sometimes use Malapropisms more for a laugh than a mistake. Here are a couple of mine:
Insulating tape = insulting tape.
Instructions = destructions (probably quite accurate in some cases).

There was also a story about a little boy in a queue with his mum who was standing next to a pregnant lady and he said "Look mum, that lady's stagnant." Love it! 

[snowdrops]

Love it GG, I too use destructions regularly.
Cucumber- bumbercue, from a child I looked after
Grandad,-Gangdad- from youngest grandson currently, mind you Grandad is a bit badass 
Sweeping brush-weeping brush as above.

[mumofstig]

There are many used here, but, I often use Cold Slaw because it's always there, lurking in the fridge 

[coldandwindy]

Love it GG, I too use destructions regularly.
Cucumber- bumbercue, from a child I looked after
Grandad,-Gangdad- from youngest grandson currently, mind you Grandad is a bit badass 
Sweeping brush-weeping brush as above.

We always grow "cow cumbers" here - what my Grandad called them.
We also eat "sparrow grass" instead of asparagus.

[Subversive_plot]

People here are better-informed these days, but years ago, people "out in the country" used medical malapropisms.  Two of  my favorites:

Smilin' Jesus  (= spinal meningitis)
Fireballs of the Eucharist (= fibroids of the uterus)

[Goosegirl]

Love the second one. Sounds like a book title!  Shall we start writing the first chapter?

[wighty]

I know it's not a  malapropism, but the clue in in my crossword this afternoon was 'a roundabout that plays music.'  I sat there for at least ten minutes thinking  of roundabouts on our road networks that play music. Couldn't come up with one, and then realised the answer was carousel!  Stupid woman.