I would go like this:
Check how many limbs of the required kind are there
Store that number
Use that number to cycle through the object limbs as many times as needed to delete them
perform checklist for object limbs 1
numberoflimbs=checklist quantity()
for n=1 to numberoflimbs-1
If limb exist(1,n)
if limb texture name (1,n)="lava.bmp"
limbcount=limbcount+1
Endif
endif
next n
for m=1 to limbcount
perform checklist for object limbs 1
numberoflimbs=checklist quantity()
for n=1 to numberoflimbs-1
If limb exist(1,n)
if limb texture name (1,n)="lava.bmp"
remove limb 1,n
Endif
endif
next n
next m
Of course if you need to delete thousands of limbs from the same object the process might become lenghty