A combination of VirtualBox, Twilio, a VPN and an old i5 laptop allows for far longer scammer frustration.
Simply give them remote access (after hiding the VirtualBox tools) then turn down the core count, memory allocation and cap execution to 10%.
Have the VM connected to the VPN at the Host end to give it Internet access without exposing your own network.
Randomly disconnect the VPN for extra hilarity.
I've had them talking for about 30mins after I've called them out on the scam and just bluntly asked how it worked.
After I get tired, I usually start making snide remarks to get under their skin. They get so angry when you make remarks about their mother.
I can't believe she raised a low-life scammer. She must have been a terrible mother.
Seriously. Don't insult the scammer. They'll just hang up. Go for family, and all of sudden, this sense of honor spews forth to defend. The exasperated sighs from helping your willfully obtuse methods stop, and the angry shouting begins.
Schoolyard insults with a scammer is a good time-waster.
You can make an otherwise boring car journey far more entertaining by having the scammer assist you rebooting your fictional router.
Also I've not tried this yet but supposedly it's now easy to log SIP devices in.
But now I'm wondering about putting them through to some ridiculous pre-recorded messages to hear the reaction...