The whole business of pressing records is/was a 'black art'. Each record label had their own trade secrets. With the appearance of CD, a lot of the know how was lost as pressing plant operators were either made redundant or retired.
Recently with the resurgence of vinyl, independent pressing plants have sprung up, using old equipment which to be truthful had seen better days, and operated by newcomers who have yet to learn the techniques of their former colleagues.
The way records are pressed differs country to country, as does their quality.
I too clean any 'new' LP on receipt and use a Decca record brush before playing. I have never had a problem with static.
As Steve says, the choice of inner sleeve is important. None are perfect, with the exception of the very expensive E-Stat carbon fibre sleeves originally distributed by Tannoy.