What is growing on my dog???

[Biggz]

My dog has a growth beside his groin, it started growing roughly 2 years ago and it is around the size of a large grape. It does not bug my dog as he never licks or touches it but it is a sight for sore eyes and we are curious as to how we can remove this safely without visiting the vet. I cant afford a $1,500.00 bill to have it tested and removed but if worse comes to worse I will have to do it. Does anyone know if tying a string around it will possibly work, I have a good friend that says its the safest method. It looks like a skin tag the way it hangs down on a thin piece of skin into a larger ball. Would tying a string around this cause complications?? All advice is greatly appreciated. Thank you.

Pictures attached.