YES!!!...i got it...it works...and it is so f***in simple, i could cry!!!
To smoothly hide dead bodies in ground it just needs.....a blackop.
For all those who like to know, here's a how to:
Create a Black Op somewhere on your map...he hasn't to be close, so put it where it can't be seen...on a offshore island i.e
Name this guy (Bodyhider i.e.)
make a script for deleting dead bodies like this one:
;delbody.sqs
?!(local server): exit
_dude = _this select 0
removeallweapons _dude
~60
bodyhider action ["hidebody", _dude]
~10
deletevehicle _dude
exit
make this script launched with eventhandler "killed"...et voilĂ ...dead bodies sink smoothly into ground before they get deleted