Possible reasons for your dog chewing everything include:

Boredom - if they don't have another dog for company when you're not there they have little or no stimulation at all.

Curiousity - like many other animals and species, puppies explore the world with their mouths by using texture and taste.

Teething - discomfort caused by teething can be alleviated by chewing.

Separation anxiety - this is the most serious cause of chewing in dogs manifested by the chewing of non-objects meaning doors, skirting boards or other structural things that may be causing "barrier frustration" and they are trying to break their way through to find you.

Anxiety - unlike separation anxiety chewing is more random and caused by a specific environmental trigger like fireworks.

But why my slippers? Do you think that a dog can distinguish between your slippers and one of their toys? Everything around a dog is a possible plaything and your slippers are the most appealing thing as they carry your scent, making them far better than any impersonal chew toy.