You are already force carbonating just by using CO2. There's two methods, low and slow, and high and fast.
High and fast is where you se your regulator to 30psi for 48 hours then down to 20 fir a day, then to your serving pressure. This can easily result in over carbed beer.
Low and slow is where you set your psi for the desired volume and let it sit for about 2 weeks. No chance of over carbing, but takes awhile.
I use low and slow for 3 reasons:
1) the extended carbonating time give the beer time to age.
2) it takes about 2 weeks for the CO2 to hydrate and produce the head properties you want.
3) no risk of over carbing