Here are some tips:

First, you can clear out the current ACLs with the following:

chmod -D /ifs/share

I think that's easier than removing each one.

Then add back in any entries following this example:

chmod +a group domain\\group_name allow dir_gen_read,dir_gen_write,dir_gen_execute,std_delete,object_inherit,container_inherit /ifs/share

Notice the double \\, this helps the shell interpret the backslash properly. This should be on all one line, not sure if the editor here will allow that or not.  But assume it is.  So do that for each entry with the correct names and properties as appropriate.

Then for CONTROL properties, do the following:

chmod -c +dacl_auto_inherited /ifs/share

chmod -c +dacl_protected /ifs/share

So, in your case, it could be a series of chmod commands, but if it's scripted, it shouldn't be too bad.

It can be a bit confusing, but once you get used to it, it's not too bad.  The man page for chmod is very good at explaining what each of the settings mean as well as syntax.  You just have to pan down to the bottom where the Isilon-specific ACL settings are.

Hope this helps.