It's hard to under-emphasize the risk of that you suggest. You are talking about places with corrupt government officials, drug gangs, paramilitary armies and street gangs galore. It's hard to say what will get you in more trouble: them knowing you have guns or thinking you don't. That equation is gonna keep inverting on you from nation to nation and area to area.
Now do I know people who have made this journey? Several times? Yeah but these are people who speak flawless Spanish, they understand these cultures and they do most of the trip dressed in rags and in bare feet. They can disappear into the culture and actually be somewhat invisible. And their stories almost ALWAYS involve long and tense hours of negotiating with happy characters here described. I wouldn't myself do that trip without a guide.
My advice? Throw everything into shipping containers, send them out of Los Angeles, fly down and pick everything up in Santiago. And up arming locally no matter what the legalistics has the advantages of stealth.
There is nothing strange about having a bar of soap in your right pocket, it's just what's happening.