I am the first person to put their hands up when it comes to admitting  they are not a good housecleaner.  I admit that I've not cleaned the  oven in 5 years  So when it started smoking slightly the past month when  using it, I bought one of those commercial oven cleaners, waiting for  the 'right' day to use it. 
The night before you are catering for a family lunch for 10 is NOT the 'right' day ! 
Because the instructions on the can said not to be left for more than  12 hours, and I leave for work at 7am and get back at 7pm, I asked 18yo  son to spray the oven when he got home from school.  This he did.  At  10pm, I judged it was time to wipe out the residue and did what I could  reach.  I then asked 18yo son to get the rest. 
Fine and Dandy I thought. 
Saturday morning, I tested the oven on a low temp, there was a  wisp of smoke, but it was free of any aroma.  I was cooking Chicken  Kievs and Scalloped Potatos - both in the oven.  I turned the oven on to  cooking temperature and shoved the whopping huge baking dish of potatos  in, filled the sink and started washing dishes.  Less than 5 minutes  later, I realised something was wrong. 
There was a bit of smoke coming from the oven.  I opened the oven  door and filled the whole house with smoke.  Not good.  Panic mode !!   MIL is due within the next 30 minutes and the house is full of smoke!!! 
I opened the front door, the kitchen window, the laundry door, the loungroom windows and remembered to turn the oven OFF. 
I rescued the potatoes from the oven.  Hmmm what to do?  I'm still  frantically trying to clean the kitchen bench down, and wash dishes, and  make house look 'nice'  - and house is full of smoke and I've got no  idea how to change the menu for 10 without an oven.  I was thinking that  a trip to the fish & chip shop was going to be the way to go. 
While I was standing outside the front door, recovering from the  brief smoke inhalation, I noticed that my lovely neighbour Narelle was  home.  There and then, in my pinny, I waltzed across the road, and  knocked on her door. 
When she stopped giggling, she was happy to let me use her oven, as  she was going out, would I lock up after I'd finished.  I trundled over  the whopping huge baking dish of potoatos and the two smaller dishes  holding the 10 kievs - slotted them into her oven and let them cook in  peace.  I was then able to clear the kitchen back down and get the house  into reasonable order before MIL showed up. 
Where was DH during all of this??  Dismantling the vacuum cleaner  because that broke too (doesn't go now at all) and trying to set up his  birthday gift - a USB picture frame, so it can play movies.  He even  joked with Narelle that he thought it was a silly time for me to decide  to clean the oven.  Did ANYBODY in my family speak up on Friday night?   Did I even hear one person say "I wouldn't do that now - the oven isn't  smoking THAT much!" 
BIL and family got slightly lost on the way here, and were a bit  bemused to see me trot over the road and return carrying lunch.  I  dished it all up and we had a lovely afternoon. 
I'm not touching the oven.  I'm leaving that to DH and 18yo - they  can clean it up.  I cannot physically get down low enough to reach the  back and top corner of it - so it's either going to be them, or I'll  find a little man in the local paper and pay him to come and clean it. 
 
go on - laugh with me.  It's funny - NOW !!