Thanks for the tips. I created a PX script in the Event Handler and only enabled the Event Subscriber so I could run it once, then disable it.  Here is the script that worked.

// Purpose: Soft delete multiple items

// Agile PLM Groovy script, using Agile SDK

// For a bunch of parts, delete them in Agile. But only delete once because doing it 2nd

// time will permenantly delete it. To permanently delete, log in to Agile, go to the

// Recycle Bin, sort by item description, find those and select that begin with "del",

// and permanently delete multiple items from there.

//

// 1. Only do this for Item Lifecycle Phase = 'Preliminary'

// 2. pitem.isDeleted() should be false, meaning only delete if it has not been marked as deleted yet

// 3. pitem.delete(); delete item and put in Recycle bin

// 4. Append "del " to front of item description so we can find these easy in the recycle bin

// 4.1 Remove last 4 chars from item description before adding "del " to avoid going over char limit
import com.agile.agileDSL.ScriptObj.IBaseScriptObj;

import com.agile.agileDSL.ScriptObj.AgileDSLException;

import com.agile.api.*;

import java.util.*;

import com.agile.px.IEventInfo;

import com.agile.px.EventConstants;

import com.agile.px.IObjectEventInfo;
import java.util.*;

import java.util.regex.*;
void invokeScript(IBaseScriptObj obj) {
IAgileSession session = obj.getAgileSDKSession();

IEventInfo req = obj.getPXEventInfo();

Integer del_cnt = 0;
try {
if (req instanceof IObjectEventInfo) {

eventInfo = (IObjectEventInfo)req;

} else {

obj.logMonitor("req IS NOT AN instanceof IObjectEventInfo");

}
if (eventInfo!=null) {
del_cnt = delItem(obj, session, "09.4761V.001", del_cnt);

del_cnt = delItem(obj, session, "21.I1021.003", del_cnt);

del_cnt = delItem(obj, session, "21.M0630.L01", del_cnt);
// ---- Add more items above, that you wish to flag as deleted and move into Recycle Bin ----
obj.logMonitor("nbr of items flagged as deleted: " + del_cnt);

}
} catch (APIException ex) {
ex.printStackTrace();

obj.logMonitor(ex.getMessage());

}

}
//

// --------- delete item ---------

//

private static int delItem(IBaseScriptObj obj, IAgileSession session, String itemnbr, Integer delcnt) throws APIException {
IItem pitem = (IItem) session.getObject(ItemConstants.CLASS_ITEM_BASE_CLASS, itemnbr);

String lifecyc = (String) pitem.getValue(ItemConstants.ATT_TITLE_BLOCK_LIFECYCLE_PHASE);
String itemdesc = (String) pitem.getValue(ItemConstants.ATT_TITLE_BLOCK_DESCRIPTION);

itemdesc = itemdesc.reverse(); // reverse all the characters, ex: ABCDEFG becomes GFEDCBA

itemdesc = itemdesc.drop(4); // remove the first 4 chars, ex: GFEDCBA becomes CBA

itemdesc = itemdesc.reverse(); // reverse it again, ex: CBA becomes ABC

itemdesc = "del " + itemdesc;
if ( lifecyc == 'Preliminary' ) {

if (!pitem.isDeleted()) {

pitem.setValue(ItemConstants.ATT_TITLE_BLOCK_DESCRIPTION, itemdesc);

pitem.delete();

delcnt = delcnt + 1;

}

}

return (delcnt);

}

You have to call delete() on an Object to put it in the recycle bin and call it again to delete it at all.
for example: for a change

IChange change= session.getObject(IChange.OBJECT_TYPE, “CO123XXX”);

//recycleBin
change.delete();

//delete at all
change.delete();

To add to Antonio, if your intention is to soft delete only. Just have a check at start for soft-deleted items so that you don’t end up hard-deleting it. 

//isDeleted() checks whether an object is deleted or not. 

If (!change.isDeleted())
{
   change.delete();  
}