Harwich started well with one of last season's stalwarts, Alfie Canning (pictured), opening the scoring in the 13th minute with a 20-yard drive that rocketed into the corner of the net.
The Shrimpers came close when, from Liam White's corner kick, Louie Bloom's header went inches past the post.
Supporters didn't have long to wait for another super goal from Harwich captain Canning, a 27th-minute thunderbolt that curled into the top of the net.
Two minutes later Harwich scored their 3rd goal when Bloom's clever through ball set up the in-form Tiwa Odufuye whose shot went just inside the far post.
Just before half time, Bloom was unlucky when his effort struck the post.
With so many trialists available, Harwich were able to field almost a new XI for the second half and again there were some impressive performances that bode well for the future.
Twelve more minutes had elapsed when two of the trialists forming the Shrimpers strike force combined well to score the 4th goal.
Harwich's well-taken 5th and 6th goals again featured these two players and the Shrimpers bosses will have been encouraged by the progress being made in pre-season in their search for a starting line-up for the coming competitive campaign.
Credit to the Clacton squad, who will be operating in a league one step lower than Harwich, and never gave up in their efforts, making it an entertaining match for the good crowd attending.
After the match, the KBF Cup was presented to Shrimpers skipper Canning.
The foundation's Malcolm Thompson conducted the raffle draw in the Social Club after the game and announced that a match-day profit of in the region of £500 for the charity - set up in memory of the former Harwich, Ipswich and England star - had been achieved. Both the foundation and the club thank everyone who contributed to this success.