Question: Retrieve elements of lists of a list ignoring []

Hello

Since my solutions are neither efficient nor concise, I wonder if someone could help me with the following problem. Suppose

 

L:=[[[],[],3,2,1,4],[1,4,[],5,8,[]],[5,6,7,8,[],1]]:

(Just a short and simplified version - L is a huge list). I need the elements to be rearranged as follows

newL:=[[1,5],[4,6],[3,7],[2,5,8],[1,8],[4,1]]:

that is, the first sublist of newL contains the first elements of all sublists of L without [], the second sublist of newL contains the second elements of all sublists of L without [] and so on.  

How can that be achieved without seq and remove?

Many thanks

Ed

PS. My solution 

newL:=[seq(remove(y->y=[],map(x->x[i],L)),i=1..nops(L[1]))]

The size of the sublists does not change.  

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