I mean make sure its all clean first tho. I even soak my bong in rubbing alcohol for few hours and even overnight on occasion. Actually ever since I learned that, ive only put bottled water or purified water in my pieces. Calcium build up is bullshit
Both.....usually I fill it up as much as I can.......n let it sit for a min or 2. Once it hits it tho, usually its instant when it comes off. Then I pour some back into a container cuz you can use it over and over again for a while (I use a old scope bottle and just leave it in there cuz you dont wanna put shit.........that just helped clean your bong back in w the good vinegar....... you use that for other stuff). So back to pouring some out......you need to cuz you cant really shake it when its full, some pour some out and just start shakin as you would w rubbing alcohol. I shake the hell out of it where it swooshes all over, becareful tho cuz all pieces are different and if you shake too hard you could break it......especially if you got tree-percs