"Blusukan" comes from the main word "blusuk" which means entry (come in) in the Java language. If this activity is done several times or repeatedly, usually this word is repeated like; "blusak-blusuk". This is almost the same as the word "ganti" (change), if it done repeatedly to become "gonta-ganti" or "balik" becames "bolak-balik".
If the word "blusuk" is positioned as a noun, the word will get suffix "-an" becomes "blusukan", is a term used to describe an activity entered into a place, then out again, and in again.