But be aware that your opponent is allowed to score a hit till the referee stops the fight. This may take a few seconds.
So if you drop your shinai then close the distance to the opponent and try to grab him.
Yes - this will also result a hansuko (for touching the opponent), but the hansukos are not cumulative and you will get one anyway (for dropping). Far better than receiving an ippon.
Kendo-Guide.Com: Thank you for your post. It is true that you can strike your opponent if he/she drops his/her shinai before the main shinpan stops the match.
About grabbing your opponent. In shiai, you do not want to lose. I completely understand it. What I think it would be better to do is to get closer or take some distance and do not let him/her strike you without grabbing. While doing so, you must not lose eye contact.