ICCF: Says nothing about it, or assistance of any kind, and you can even use computers legally. Here are their rules.
USCF: "3. You may consult chess books and periodicals but not other players." Here are their rules.
With regards to the ICCF rules, my guess is that they just decided it was too hard to police computer used, so they just allow it. ...
Obviously, as long as they are permitted within the rules of the organization, here is how I would use a computer.
First, realize that different programs are better at different things, and I will divide them into two categories. I heard GMs Peter Svidler and Jan Gustafsson discuss this during the Firouzja-Carlsen game just yesterday.
The first program is ...
All correspondence chess always allowed written materials.
Now they may also allow computers, and AFAIK also do so as it would be impossible to know if someone was using one or not.
Many people now complain that CC is just one computer versus another.
I always suspected that Hans Berliner had used a computer when he worked at FSD in Gaithersburg ...
Note: This was answered before the OP edited the question, and specified it was an online competition.
According to ICCF (international) rules, yes, it is still a draw.
6.7 Except where one of the Articles 5.1 or 5.2 applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by the player. However, the ...
This is by no means complete, but here's a few things.
Use at least 2 engines. More different is generally better. Lc0 and SF would be an obvious pair.
Especially with leela, look at the point of view of the engine. Dig into disagreements.
Realize most of your games will be draws
Make sure you have tuned your engines for long time control. For leela, that ...