This is a technique that can be used as soon as multiple doubles are on the board. It requires you to follow mates of doubles with a two colour scheme in our case light grey/green and light blue.
Finding the right block to start may be difficult but in the example it worked out to be the first from top left to right bottom. (The Start block is indicated in Grey.
Pink indicate where both light grey/green and light blue get together in the same cell and number. Yellow mean elimination and is numbers outside the chain with both colours crossing it.
The pc is quite good at this but with some practise the human can get good and eliminate enough to get to a solution.