Question on factorint matrix modification

A recursive function g(n) will call g(n/q) for each prime divisor q of 
n.

It can do so with: F=factorint(n)[,1];foreach(F,q,g(n/q))
But that way each invocation of g() has to factorint its argument and 
those numbers are big.

I want to factor top n once and pass factorization matrix additionally.
Just found one way to compute the reduced factorization matrix:

? F=factorint(2^3*7*19^2);
? print(F)
[2, 3; 7, 1; 19, 2]
? dec(f,i)=if(f[1]==i,[i,f[2]-1]~,f);
? 
for(i=1,#F~,M=Mat([g|f<-F~;g<-[dec(f,F~[1,i])],f[1]!=F~[1,i]||f[2]>1])~;print(M))
[2, 2; 7, 1; 19, 2]
[2, 3; 19, 2]
[2, 3; 7, 1; 19, 1]
?

That does what I want and I am happy to have found it.
But it looks a bit complex to me for the task.
Is there a simpler GP way to determine the factorization matrix of n/q 
from F?
Is there a way without matrix comprehension?

Regards,

Hermann.