I dont think grips would be advisable with any at home setup of 3d printing. Reductive (milling or cnc) would probably be a better way. Far more sturdy.
At home 3d printing can be done with different types of plastics, but the most durable plastics get very tricky to print correctly, or have fumes, or need special environmental temp controls.
The the two most basic types of home printing is done in PLA and ABS. PLA is by far the easiest, that's what I do all my printing with. However, over time and depending on exposure to the elements and/or prolonged direct sunlight, PLA can be come brittle and fail. Also, it doesn't do well with heat. So you couldn't print something like an AR handguard and expect it to last.
PLA has its place though. All the do-dads I have made are doing fine after a few years. Also PLA is very biodegradable, If I remember correctly it's made of corn or some by product.