I'm pretty sure a buzzing doormat would put me off stepping on it if I didn't understand why it was doing it. It could be a barrier to her wanting to go outside.
I'd add, kennel training can help with toilet training, in as much that a dog will
prefer not to toilet where she sleeps. But, it's not a silver bullet solution - if she has to toilet, she has to toilet; whether she is in there or not.
I'd agree with
@Laco that you should look closely at your toilet training.
Take her out more often than she needs, so she is never so full she can't hold.
Don't wait for her to tell you, be proactive.
If you take her out and she doesn't toilet, bring her back in but don't take your eyes off her - any hint of wanting to toilet, scoop her up and get her out fast.
If she doesn't try to toilet indoors, take her out again 10 minutes later. Repeat these steps until she toilets outside.
This is the important part. When she does toilet, reward her
immediately and
generously. It has to be immediate to be clear that it's for toileting and not for anything else and it has to be generous to make it worth her while to hold her toilet until she is outside. Maybe get a new reward (frankfurter sausage?) that's only used for outside toilets. And to a dog, several tiny pieces seem to have more value that one bigger piece of equivalent size.
If she has an accident inside, don't react. Getting cross or scolding can make dogs just avoid you when they need to toilet, so it's completely counterproductive. They will just seek or create opportunities to toilet when you are not there.
Just clean up any accidents with an enzymatic cleaner and leave it down for 10 minutes to let the enzymes get to work before you wipe it up.