One tip with planking or ball swirl.

Its very tempting to apply some meths to the ME and attack the PF straight away and then rub the ME .

In all honesty, this does nothing at all apart from clean the very top surface.. and trust me.. this will get VERY clean after the work.

If you want to get the ingrained dirt out then you have to dissolve it first.. after all, if the cleaning agent never reaches the dirt, its not coming out right?

What i do is apply meths with a rag very liberally and allow to soak in... its meths and so its never there too long to expand the timber much... what this does though is attack the grease and dirt for you loosening it up.
THEN go in with the ME and meths along the lines of the planking... the ME is a super absorber and literally sucks the dirt out.
But if you havent loosened the dirt already, then all you are doing is a mild abrasive to the PF while waiting for the solvent to reach the dirt.. ME wont work until this happens.

Sugar Soap and warm water is also very very good.. can even use the Sugar soap neat but its quite thick and cant always reach the bottom of your crack ( LOL.. no pun intended) which is why i thin it down slightly... pulls dirt out like you wouldnt believe.

ME is only really there as your absorber.. remember that and youll save a lot more paint on your PF