I would say no, if you put clear nail polish into the port area, it will very likely gum up the mechanism before setting and you won't be able to get it out.
You might be able to put clear nail polish on the head of the titan to 'thicken it up' but I'm not sure what the long term effect would be.
I have found on most figures, that if you connect the titan with the head turned 180 degrees it's a tighter fit, on some it's too tight and on others it overcomes the extra loose connection.
The heads are not quite square and the connection port has a thinner section and a wider section.