dirty barrel j&j ceramic

so i bought my new barrel finnally.  i fired several rounds through it and had the first break in my a-5 ever.  now i ran a squeegie through the barrel, but there are still some spots inside the barrel.  can i wash it with soap and water, or do i need to do somthing else.  also, will an a-5 start to lose velocity in the shots when the co2 tank is low but still enuff to run it.  my shots started to drop alot fast without all the distance, but then i ran out of air within like 20 shots, so i figure that's the problem there.  any help would be great.

Run warm water though it, and roll up half a paper towel and push it through.

The tank problem you had is a common occurance. There was no liquid co2 left to expand and you were running it on 800psi- of gas. It will happen whenever you get close to out.