There is a much simpler and more correct way to fix your problem than using the poly sculpt tool which is time consuming and a frame by frame solution most of the time...
What you need to do is one of two things or both depending on your collision surfaces. First it appears your collision surfaces are NURBS so I would open the collision attributes assigned to the surface of the body uder the shirt, the maun piece or pieces that make up the upper body, no need to include the arms unless you start to see problems there... Anyway find the nurbs tesselet attribute under the collision attribute and change it to 3 spans per in U and V (this will tells maya when it simulates the cloth and converts the nurbs to polys for collision reference against the cloth that there is a more solid and better defined surface to reference against because the representing facets are much smaller and grouped better together.) Then select the panels of the cloth shirt that make contact with the sides of the body and increase the tesselation factor in those panels only. (only increase a little at a time, will start to see a time difference in solving "though in my opinion the higher the res, the better...")
The other is if you have or had a patch based surface for collision surfaces you sometimes get an effect like that along the seems- the trick there is to assign different collision priorities to each surface so no two touching patches have the same priority, depending on how a patch based collision surface is put together and animated, there is sometimes even a need to animate the priority numbers over time to create the correct effect - esspecially in situations like arms moving around the side of a character in a rubbing like effect- if your collision priority was the same in the arm surface that it is in the torsoe surface as they cross eachother, maybe even make some surface penetration your cloth would explode and tear, if they had different priorities the surface with the lower priority number would be the surface calculated when solving a simulation while the sim ignors the other. "Making cloth simulation Ohh so much simpler.."
-one small addition would be adjusting your solver scale up or down a little if the speed of your machine drops to a crawl because of the above, as well as keeping your grid in the perspecrive view set to the default size...
-Hope it helps