Sidhwa's title carries significance in both the novel and the thematic applications of it.  On one hand, the "ice candy man" is an important character in the novel.  He is the one who is able to engender the trust of Lenny in confessing where her Ayah is hiding.  In a poignantly brutal moment, he tells her that he will help her Ayah, convincing Lenny to do  something which will turn out to be just the opposite.  The "ice candy man" is representative of how volatile the populace was during the time of Partition.  His presence and thus the book's title helps to explain how a nation that had won independence in a nonviolent manner could end up plunging into an orgy of violence and a savage brutality following it.  At the same time, Sidhwa wants to indict the politicians who designed Partition as a politically expedient reality as opposed to examining the human cost of such a move. For them, these individuals are the real "ice candy men" who were able to sell something that was "ice" as "candy."   Additionally, the title suggests "ice" underneath the exteriror of these men, individuals who fully understood the implications of what they were doing and did little, if anything, to stop the murders, rapes, and plundering that resulted because of Partition.  Finally, I think that Sidhwa's title having to be renamed as "Cracking India" because of its potential for drug associations helps to explain how the understanding of Partition, even in the modern setting, is a challenging one, often ladled with confusion and misunderstanding.