I don't see the point of the hose. Just blow into the bottle. By attaching a hose you're only going to have more space for 'unsploofed' smoke to collect. You'll have to take an extra breathe to push that out as well as what is still left in the bottle. The whole point of the sploof is to not let smoke enter your room unless it passes the dryer sheets. It's just not going to make the sploof any more efficient. If you cut off the bottom of another 2 liter and put carbon in it, then taped that around the bottom of the existing 2 liter and put a screen on both sides of that chamber so the carbon didn't fall into the sploof or out of it then that would make it more efficient. If you're stoned and dead set on trying this then go for it. I just don't see the point. It's also going to restrict air flow and make it harder to blow out.
My idea was that the farther the smoke Is from you, the less you will smell. Like you could hang it out your window. I live with the rents still soo
Get a square shaped fan and point it out the window. Use a pillow or something to block off the rest of the window, always smoke near this with your door closed, and do not put a towel under the door. Leave the fan on for about 30 mins after you finish smoking. Also remember that if you handle any weed in your room to have the fan on and be near it. Sploofs never worked for me. I know some people swear by them, but either they have parents that don't care, or stupid parents. Back in the day when my parents still cared, I got caught all the time using sploofs and simply blowing out the window. Out of respect I still use the fan because they simply don't want to smell it at all. They won't punish me but they'll be pretty irritated when their house smells like my drugs. It's a respect thing.
Use a paper towel tube then roll paper towels up and then stuff them in there real good like then put some dryer sheets on the end with a rubber band. it eliminates all the smoke but you have to make sure you have enough paper towels or it wont eliminate the smoke. i use it everyday trust me it works